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KVM: x86: Use a u64 when passing the MMIO gen around

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KVM currently uses an 'unsigned int' for the MMIO generation number
despite it being derived from the 64-bit memslots generation and
being propagated to (potentially) 64-bit sptes.  There is no hidden
agenda behind using an 'unsigned int', it's done simply because the
MMIO generation will never set bits above bit 19.

Passing a u64 will allow the "update in-progress" flag to be relocated
from bit 0 to bit 63 and removes the need to cast the generation back
to a u64 when propagating it to a spte.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2019-02-05 13:01:15 -08:00 committed by Paolo Bonzini
parent 361209e054
commit 5192f9b976
1 changed files with 7 additions and 7 deletions
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14
arch/x86/kvm/mmu.c
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@ -348,20 +348,20 @@ static inline bool is_access_track_spte(u64 spte)
#define MMIO_GEN_LOW_MASK ((1 << MMIO_GEN_LOW_SHIFT) - 2)
#define MMIO_GEN_MASK ((1 << MMIO_GEN_SHIFT) - 1)
static u64 generation_mmio_spte_mask(unsigned int gen)
static u64 generation_mmio_spte_mask(u64 gen)
{
u64 mask;
WARN_ON(gen & ~MMIO_GEN_MASK);
mask = (gen & MMIO_GEN_LOW_MASK) << MMIO_SPTE_GEN_LOW_SHIFT;
mask |= ((u64)gen >> MMIO_GEN_LOW_SHIFT) << MMIO_SPTE_GEN_HIGH_SHIFT;
mask |= (gen >> MMIO_GEN_LOW_SHIFT) << MMIO_SPTE_GEN_HIGH_SHIFT;
return mask;
}
static unsigned int get_mmio_spte_generation(u64 spte)
static u64 get_mmio_spte_generation(u64 spte)
{
unsigned int gen;
u64 gen;
spte &= ~shadow_mmio_mask;
@ -370,7 +370,7 @@ static unsigned int get_mmio_spte_generation(u64 spte)
return gen;
}
static unsigned int kvm_current_mmio_generation(struct kvm_vcpu *vcpu)
static u64 kvm_current_mmio_generation(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_memslots(vcpu)->generation & MMIO_GEN_MASK;
}
@ -378,7 +378,7 @@ static unsigned int kvm_current_mmio_generation(struct kvm_vcpu *vcpu)
static void mark_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 gfn,
unsigned access)
{
unsigned int gen = kvm_current_mmio_generation(vcpu);
u64 gen = kvm_current_mmio_generation(vcpu);
u64 mask = generation_mmio_spte_mask(gen);
u64 gpa = gfn << PAGE_SHIFT;
@ -426,7 +426,7 @@ static bool set_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn,
static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte)
{
unsigned int kvm_gen, spte_gen;
u64 kvm_gen, spte_gen;
kvm_gen = kvm_current_mmio_generation(vcpu);
spte_gen = get_mmio_spte_generation(spte);